Fading is usually a dynamic function of the state of the ionosphere for a particular incoming vertical angle to your station.
Fading is very pronounced for local contacts when using a dipole at 1/2 wave above ground. This is becuz the main antenna lobe is very low compared to the local incoming high angle stuff. Thus, as Jim said, having a weak signal to work with makes it easier to drop into the noise floor vs: a stronger signal. It's kind of an illusion sometimes.
The [impractical] solution is to have more than one antenna in instantaneous diversity, thus having the potential to grab an edge in the higher angles and in the lower angles as they happen. There must be an active selection process or else it gets watered down if they're all on at the same time, just like if you tied six Yagis together, all in different directions producing an omni pattern again - the power/signal simply splits between them. But, two antennas tied together at zero degrees phased, at totally different heights may overlap well and provide only a -3db loss in overall pattern vs: one. Plus, that nice filled in pattern is much better than to have a -15 or -20db hole using only one antenna optimized for the job. Depends upon what you wanna do. Usually, one antenna for DX and one for local is the rifle approach vs: shotgun.
Probably the best SINGLE antenna for all around local and farther out USA work for 160M would be the same as on 75M, only scaled up. A dipole at 160' high. This is the equaivalent to a dipole at 80' on 75M. This has a good mix of both high and low angle components with a max lobe at about 45 degrees or so. This is a tough feat to pull off, of course.
A vertical with ground radials is, of course, the best antenna for long haul DX on 160M... hands down. Even better than a Yagi at 240' cuz of the approx -10 db Earth absorption of horiz polarization vs: vertical. On 75M and above it's just the opposite and high Yagis rule.
So, bottom line is that on 160M, controlling antenna takeoff angle is VERY difficult since you need to get the horizontal antenna up 120' JUST for 1/4 wave above ground. At 1/4 wave high, the antenna shows just a little difference in vertical angles from 1/8 wave high. [60'] There will be times when a dipole at 240' is needed for the proper match up to the ionosphere at that particular time. A vertically polarized antenna has such drastically low angles that it is impractical for local work and will be weaker the vast majority of the time.
So, just get the horizontal antenna up as high as possible on 160M and try to grab as much low angle as possible - the high angle stuff will be well taken care of already if below 120' up.
As far as a lower antenna having more fading.... again, it just depends upon the incoming angle. It the angles incoming are very high, the low dipole will have less fading than the higher one, assuming the match up at that time is within it's range. With three stations in a QSO with you, the odds of all stations having the same optimum vertical angle into you for any length of time are nil. So, someone is usually gonna be PW until the ionosphere changes and the next guy is PW, and so on...
T
